Linear motion, re-circulating ball, sliding support assemblies are known in the art. Such support assemblies allow a variety of potential setups to be achieved in order to move objects along a linear rail. Such rails can be made from extruded lengths of aluminium of, for example, 1 m or 2 m in length. The lengths of rail can be cut to length, drilled or machined as required by the user.
Such sliding supports include a slide cassette and a plurality of bearing balls. The slide cassette may be made from one or two polymer or resin components, and/or a stainless steel, nitrided steel, or aluminium member. The slide cassette can be arranged within a length of rail chosen by the user.
For example, U.S. Pat. No. 4,701,057 discloses a sliding support assembly comprising a linear rail having a web and a pair of flanges. The inner surface of each flange includes a first linear guide groove. The assembly includes a slider unit including a pair of endless circulating paths in which a plurality of bearing balls can move. The slider unit includes a main body comprised of upper and lower body sections, in which the endless paths are defined, and a frame attached to the main body. The frame comprises a channel-section member having a pair of linear second guide grooves formed in the outer surface of the member's flanges. The linear second guide grooves extend in opposed relation to the corresponding first guide grooves, and partly define the endless paths. Similar slide assemblies are disclosed in U.S. Pat. No. 5,518,317 and EP 1 363 036.
In all of the known re-circulating ball slide assemblies which have a slide cassette arranged within a rail, there is no mechanism for preventing the ingress of dirt into the ball paths, and no mechanism for retaining lubricant within the ball paths.
Accordingly, there is a need for an improved re-circulating ball sliding support assembly in which the ball paths are sealed against the ingress of dirt, and the lubricant is retained within the ball paths.